Adaptive Margin and Band Control

ABSTRACT

Configuration or otherwise controlling parameters of a DSL system related to power, band usage and margin is based on collected operational data. Operational data are collected from at least one DSL system operating under a known configuration and/or a profile. A target profile is selected based on binder-level information. The collected operational data is analyzed and conditions for changing the DSL system configuration to the target profile are evaluated, including any applicable transition rules pertaining to changing profiles. If the conditions hold, then the DSL system is instructed to operate with the target profile. Binder-level information can include deployment point information, topology information, and/or crosstalk coupling information. The controlled parameters may have values that are chosen using one or more spectrum balancing methods. Such spectrum balancing methods may be executed infrequently, and may make use of all binder-level information that is available.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 10/893,826(Attorney Docket No. 0101-p04) filed on Jul. 19, 2004, entitled ADAPTIVEMARGIN AND BAND CONTROL, which claims the benefit of priority under 35U.S.C. §119(e) of U.S. Provisional No. 60/527,853 (Attorney Docket No.0101-p01p) filed on Dec. 7, 2003, entitled DYNAMIC MANAGEMENT OFCOMMUNICATION SYSTEM, the disclosures of which are incorporated hereinby reference in their entirety for all purposes.

This application claims the benefit of priority under 35 U.S.C. §119(e)of the following:

-   -   U.S. Provisional No. 60/698,113 (Attorney Docket No. 0101-p28p)        filed on Jul. 10, 2005, entitled DSL SYSTEM, the disclosure of        which is incorporated herein by reference in its entirety for        all purposes; and    -   U.S. Provisional No. 60/723,415 (Attorney Docket No. 0101-p29p)        filed on Oct. 4, 2005, entitled DSL SYSTEM, the disclosure of        which is incorporated herein by reference in its entirety for        all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISK APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to methods, systems and apparatus formanaging digital communication systems. More specifically, thisinvention relates to adaptive control of various transmissionparameters, including but not limited to maximum transmit power spectraldensity, maximum aggregate transmission power, transmission bandpreference, minimum and maximum receiver margin, frequency-dependentbit-loading and power controls and/or bit-loading restrictions incommunication systems such as DSL systems.

2. Description of Related Art

Digital subscriber line (DSL) technologies provide potentially largebandwidth for digital communication over existing telephone subscriberlines (referred to as loops and/or the copper plant). Telephonesubscriber lines can provide this bandwidth despite their originaldesign for only voice-band analog communication. In particular,asymmetric DSL (ADSL) can adjust to the characteristics of thesubscriber line by using a discrete multitone (DMT) line code thatassigns a number of bits to each tone (or sub-carrier), which can beadjusted to channel conditions as determined during training andinitialization of the modems (typically transceivers that function asboth transmitters and receivers) at each end of the subscriber line. Theadaptive assignment can be continued during live data transmission onchannels or lines that vary with time using a process often referred toas “bit-swapping” that uses a secure relatively low-speed reversechannel to inform the transmitter of assignment changes.

Impulse noise, other noise and other sources of error can substantiallyimpact the accuracy of data transmitted by DSL and other communicationssystems. Various techniques have been developed for reducing, avoidingand/or repairing the damage done to data by such error duringtransmission. These error reduction/avoidance/repair techniques haveperformance costs for a communication system in which they are used. Asis well known in the art, inadequate power transmission levels lead toerrors because the transmission power is not high enough to overcomenoise and other interference in a given channel. These errors lead tolost data and/or the need for re-transmission of data, sometimesmultiple times. To prevent such errors, systems utilize extratransmission power that results in margins above a known or calculatedsignal-to-noise ratio (SNR) that assures compliance with an acceptableerror rate.

Excessively high power transmission levels, however, lead to otherproblems. For example, use of transmission power above necessary levelsmeans that the communication system is operated more expensively, to thedetriment of all users. In addition, one or more lines' use of excessivetransmission power can generate strong crosstalk problems andinterference in nearby lines. Crosstalk is unwanted interference and/orsignal noise electromagnetically passed between lines that share thesame or adjacent binders. Crosstalk can be categorized as far-endcrosstalk (FEXT) or near-end crosstalk (NEXT). FEXT is particularlydetrimental in certain loop configurations with different lengths. Onesuch situation is when a first DSL service (for example, a DSL loop orline) is deployed from a central office (CO) and a second DSL service isdeployed from a remote terminal (RT), a service access interface (SAI),an optical network unit (ONU), a pedestal or any other location outsidea CO. In such situations, FEXT from the CO-deployed service may causeconsiderable degradation to a service deployed from the non-CO location.Another strong FEXT situation arises with short to medium loop lengths,when a short line can cause strong interference into the receiver of alonger line. One such situation arises when VDSL service is deployed onloops with different lengths, in which case the FEXT crosstalkinterference can be particularly strong in the upstream direction. NEXTcan have a damaging effect in DSL configurations where there is someoverlap between the bands used for transmission in the downstream andupstream direction, or where there is signal leakage from a downstreamtransmitter to an upstream receiver or vice versa.

Systems, devices, methods and techniques that allow users to adjust andadapt transmission power margin(s), power spectral densities, and thelike dynamically to changing DSL environmental and operationalsituations would represent a significant advancement in the field of DSLoperation. Moreover, monitoring and evaluation of the power, margins,etc. used in the DSL environment and operation by an independent entitycan assist, guide and (in some cases) control users' activities andequipment, and likewise would represent a significant advancement in thefield of DSL operation.

BRIEF SUMMARY OF THE INVENTION

Configuring or otherwise controlling, parameters of a DSL system relatedto power, band usage and margin is based on collected operational data.Operational data are collected for at least one DSL system operatingunder a known configuration and/or a profile. A target profile isselected based on binder-level information. The collected operationaldata is analyzed and conditions for changing the DSL systemconfiguration to the target profile are evaluated, including anyapplicable transition rules pertaining to changing profiles. If theconditions hold, then the DSL system is instructed to operate with thetarget profile. Binder-level information can include deployment pointinformation, topology information, and/or crosstalk couplinginformation. Collected operational data may include reported modemparameters and/or available modem capabilities such as bit loadingprocedures, DSL service priorities and others. The controlled parametersmay have values that are chosen using one or more spectrum-balancingmethods. Such spectrum-balancing methods may be executed infrequently,and may make use of all binder-level information that is availableand/or of collected operational data.

Embodiments of the present invention include apparatus and other devicesconfigured to execute and/or perform the above-referenced methods. Forexample, methods according to the present invention may be performed bya controller, a DSM Center, a “smart” modem, a DSL Optimizer, a SpectrumManagement Center (SMC), a computer system and the like. Moreover,computer program products for performing these methods also aredisclosed.

Further details and advantages of the invention are provided in thefollowing Detailed Description and the associated Figures.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings,wherein like reference numerals designate like structural elements, andin which:

FIG. 1A is a schematic block reference model system according to theG.997.1 standard.

FIG. 1B is another schematic block reference model system.

FIG. 2 is a schematic block diagram illustrating a generic, exemplaryDSL deployment.

FIG. 3A is a controller including a model-based control unit accordingto one embodiment of the present invention.

FIG. 3B is a DSL optimizer according to one embodiment of the presentinvention.

FIG. 4 is a flow diagram of methods according to one or more embodimentsof the present invention.

FIG. 5 is another flow diagram of methods according to one or moreembodiments of the present invention.

FIG. 6 shows the design and/or selection of one or more transitionmatrices and allowable profiles for use in connection with embodimentsof the present invention.

FIG. 7 is an exemplary overall rule utilizing various sub-rules to yielda decision as to whether or not a target profile is feasible in someembodiments.

FIG. 8 is a flow diagram showing one or more embodiments of the presentinvention in which transitioning operation of a DSL line or othercommunication line from a current state to one or more target states isevaluated.

FIG. 9 is an exemplary state diagram for use in connection withembodiments of the present invention.

FIG. 10 is an exemplary set of DSL line profiles.

FIG. 11 is a block diagram of a typical computer system suitable forimplementing embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of the invention will refer to one ormore embodiments of the invention, but is not limited to suchembodiments. Rather, the detailed description is intended only to beillustrative. Those skilled in the art will readily appreciate that thedetailed description given herein with respect to the Figures isprovided for explanatory purposes as the invention extends beyond theseillustrative embodiments.

It should be kept in mind that the specifics provided herein are forpurposes of illustration and that the present invention is broader thanany one example. Therefore, the present invention should be construed asbroadly as possible and permitted.

Generally, embodiments of the present invention will be described inconnection with the operation of a DSL system having a controller (forexample, a computer system or control processor, which may or may not beembedded into a DSLAM or DSL Access Node or other network element, a“smart” modem, a dynamic spectrum manager, a DSL optimizer, a SpectrumManagement Center (SMC), and/or a Dynamic Spectrum Management Center(DSM Center) as described in publications and other documents relatingto this field, or any other suitable control device and/or entity,including a computer system). When the term “controller” is used herein,it is intended to mean any or all of these or any other suitable controlmeans. A controller may be a single unit or combination of componentsthat are a computer-implemented system, device or combination of devicesthat perform the functions described below.

As will be appreciated by those skilled in the art, after reading thepresent disclosure, embodiments of the present invention may be adaptedto operate in various DSL and other communication systems known to thoseskilled in the art. A dynamic spectrum manager or other controllermanaging a communication system using one or more embodiments of thepresent invention may be a service provider and/or operator (which insome cases may be a CLEC, ILEC or other service provider) or may be aparty partially or completely independent of the system operator(s).

Generally, when more parameters are monitored and adjustable in a DSLsystem, rather than being statically set, performance can be improved,often dramatically (for example, higher data rates can be realized, moreusers can be serviced, less power may be consumed, etc.). That is, ifsystem settings are set adaptively as a function of the performancehistory and other information about a line or channel, adaptive changesto system operation can improve the data rates and other service forusers. Systems according to embodiments of the present invention thataccept and analyze more inputs and become, in essence, dynamic functionsof a few parameters based on the observation and processing of the manyother observed parameters and history of the line performance constitutea significant improvement in this field.

To reduce performance problems of various types, including crosstalkinterference, many communication systems limit the power that may beused by transmitters sending data within a given system. The margin of atransmission system is the level of transmit power (typically expressedin dB) over the minimum power needed to achieve a desired performance(for example, a threshold bit error rate, or BER, of the system). Thebasic goal is to use sufficient power to overcome and/or compensate fornoise-induced errors and interference-induced errors, while minimizingthe power needed for transmission to reduce the potential problemsoccasioned by excessive levels of transmission power. In many cases,however, equipment manufacturers, system operators and others use suchexcessive power (leading to excessive margins) in an effort to providehigh data rates and to take a simplistic approach to dealing withpotential problems like crosstalk.

The present invention uses information about DSL line characteristics(for example, operational data, knowledge of DSL modem capabilities,etc.) to evaluate more carefully acceptable problem/interferenceavoidance, mitigation, reduction, etc. and data rates in power-adaptivesystems and methodologies. This more careful evaluation analyzes theavailable information and/or operational data and then trains and setsmodems to operate at power transmit levels (and thus margins) that willprovide sufficient power for acceptable data transmission whileminimizing the deleterious effects that electromagnetically radiatedcrosstalk from one user's line might have on other users' lines. Morespecifically, embodiments of the present invention can generatemargin-related and/or power-related parameters and instruct at least onemodem in a modem pair to use one or more such margin-related and/orpower-related parameters to assist the modem pair in meeting a givenmargin target and/or in reducing the radiated crosstalk on other modempairs. A “margin-related parameter” can include (but is not necessarilylimited to) parameters for line configuration and parameters for channelconfiguration as defined in the ITU-T G.997.1 (G.ploam) recommendation.The margin-related parameter may also include controls as defined in thedraft ATIS Dynamic Spectrum Management Technical report, NIPP-NAI-028R2.Finally, the margin-related parameter may include controls such astarget SNR margin per tone, bit-cap per tone, margin cap mode, PREFBANDand others.

In embodiments of the present invention, configuration and/or othercontrol of DSL system parameters related to power, band usage and marginis based on collected operational data. Operational data are collectedfrom one or more DSL systems operating with one or more current and/orknown configurations (also referred to as profiles), and may includereported parameter values such as line failure parameters, lineinventory parameters, line/channel/data path performance monitoringparameters, line/channel test, diagnostics and status parameters.Operational data may also include reported, indicated, advertised, orotherwise known modem capabilities including bit loading procedures,modem service priorities, modem compliance with certain rules andothers. A target and/or potential profile is selected based onbinder-level information (for example, from a set of profiles that areallowed based on the binder-level information). The collectedoperational data is analyzed and conditions for changing the DSL systemconfiguration to the target profile are evaluated. If the conditionshold (that is, if the target profile is available, for example in lightof collected operational data, profile transition rules, etc.), then theDSL system is instructed to operate with the target profile. The processof evaluating conditions may be repeated for multiple target profiles.Embodiments of the present invention can be used in connection withADSL1, ADSL2, ADSL2+, VDSL1, VDSL2 and other types of DSL systems andequipment.

A controller also can collect the binder-level information from a systemof the service provider or network operator, such as an OperationsSupport System, a wire-map database, a topology information databaseincluding those that may be available generally on public internetsearch engines, a Geographic Information System (GIS) database, a DSMcenter database, or any other suitable source. Binder-level informationcan include deployment point information, topology information, and/orcrosstalk coupling information. Controlled parameters can include aPSD-related or power-related value, such as the MAXNOMPSD or MAXNOMATPparameter used by various DSL systems. In some embodiments, thecontrolled parameters may be a shaped spectral mask for use intransmissions and/or may be caps or limits on bit loading forfrequencies used in transmissions between the modems. In some cases,preferred bands can be imposed to direct modems to favor and/or avoidcertain frequencies.

The operational data may include historical data relating to priorperformance of the DSL system. The historical data may be maintained ina database, library, etc. The operational data may further include datacollected from the broader system in which the DSL system operates, forexample from one or more MIBs or other data sources. The operationaldata may be sent to the controller by communication means internaland/or external to the DSL system itself. Some other types ofoperational data that can be evaluated include data pertaining to datarate, maximum attainable data rate, margin, code violations and FECcorrections of the DSL system and of its neighboring DSL systems.Additional operational data may include indications of modemcapabilities or of modem features or of modem modes of operation. Modemsmay report such indications at various stages during DSL modeminitialization such as “handshake” (as explained in the ITU-Trecommendation G.994.1 or G.HS). Such indications may be provided duringnormal modem operation (“showtime”) via messages sent over the modem'sembedded operations channel and reported to the network managementsystems or Spectrum Management Centers over interfaces such as definedin ITU-T Recommendation G.997.1 (also know as G.PLOAM). Alternately,modem capabilities for various modem types (identified by equipmentmanufacturer, chipset manufacturer, firmware version, serial number andothers) may be known from databases, libraries, etc. The controlledparameters may have values that are chosen through knownspectrum-balancing methods. In some embodiments such methods areadvantageously executed infrequently, making use of all binder-levelinformation that is available.

FIG. 1A shows a reference model system, with which embodiments of thepresent invention can be used, according to the G.997.1 standard (alsoknown as G.ploam), which is well known to those skilled in the art. Thismodel applies to all DSL systems meeting the various standards that mayor may not include splitters, such as ADSL1 (G.992.1), ADSL-Lite(G.992.2), ADSL2 (G.992.3), ADSL2-Lite G.992.4, ADSL2+(G.992.5) and theG.993.2 VDSL2 standard. This model can also be applied to the G.993.1VDSL1 standard, as well as to the G.991.1 and G.991.2 SHDSL standards,and to any DSL system with and without bonding. This model is well knownto those skilled in the art.

The G.997.1 standard specifies physical layer management for DSLtransmission systems based on the clear, embedded operation channel(EOC) defined in G.997.1 and use of indicator bits and EOC messagesdefined in G.99× standards. Moreover, G.997.1 specifies networkmanagement elements content for configuration, fault and performancemanagement. In performing these functions, the system uses a variety ofoperational data (which includes performance data) available at anaccess node (AN).

In FIG. 1A, users' terminal equipment 110 (sometimes also referred to as“customer premises equipment” or CPE) is coupled to a home network 112,which in turn is coupled to a network termination unit (NT) 120. NT 120includes an ATU-R 122 (for example, a transceiver defined by one of theDSL standards) or any other suitable network termination modem,transceiver or other communication unit. NT 120 also includes amanagement entity (ME) 124. ME 124 can be any suitable hardware device,such as a microprocessor, microcontroller, or circuit state machine infirmware or hardware, capable of performing as required by anyapplicable standards and/or other criteria. ME 124 collects and stores,among other things, operational data in its MIB, which is a database ofinformation maintained by each ME, and which can be accessed via networkmanagement protocols such as SNMP (Simple Network Management Protocol),an administration protocol used to gather information from a networkdevice to provide to an administrator console/program or via TL1commands, TL1 being a long-established command language used to programresponses and commands between telecommunication network elements.

Each ATU-R in a system is coupled to an ATU-C in a CO or other centrallocation. In FIG. 1A, ATU-C 142 is located at an access node (AN) 140 ina CO 146. An ME 144 likewise maintains an MIB of operational datapertaining to ATU-C 142. The AN 140 may be coupled to a broadbandnetwork 170 or other network, as will be appreciated by those skilled inthe art. ATU-R 122 and ATU-C 142 are coupled together by a loop 130,which in the case of ADSL typically is a telephone twisted pair thatalso carries other communication services.

Several of the interfaces shown in FIG. 1A are used for determining andcollecting operational data. The Q-interface 155 provides the interfacebetween the Network Management System (NMS) 150 of the operator and ME144 in AN 140. Such an NMS may contain within or may be connected to aDSM Center, DSL optimizer, or any other controlling entity of the typein this invention. The G.997.1 standard specifies parameters that applyat the Q-interface 155. The near-end parameters supported in ME 144 arederived from ATU-C 142, while the far-end parameters from ATU-R 122 canbe derived by either of two interfaces over the U-interface. Indicatorbits and EOC messages, which are sent using embedded channel 132 and areprovided at the PMD layer, can be used to generate the required ATU-R122 parameters in ME 144. Alternately, the operations, administrationand maintenance (OAM) channel and a suitable protocol can be used toretrieve the parameters from ATU-R 122 when requested by ME 144.Similarly, the far-end parameters from ATU-C 142 can be derived byeither of two interfaces over the U-interface. Indicator bits and EOCmessages, which are provided at the PMD layer, can be used to generatethe required ATU-C 142 parameters in ME 122 of NT 120. Alternately, theOAM channel and a suitable protocol can be used to retrieve theparameters from ATU-C 142 when requested by ME 124.

At the U-interface (which is essentially loop 130), there are twomanagement interfaces, one at ATU-C 142 (the U-C interface 157) and oneat ATU-R 122 (the U-R interface 158). Interface 157 provides ATU-Cnear-end parameters for ATU-R 122 to retrieve over the U-interface 130.Similarly, interface 158 provides ATU-R near-end parameters for ATU-C142 to retrieve over the U-interface 130. The parameters that apply maybe dependent upon the transceiver standard being used (for example,G.992.1 or G.992.2). The G.997.1 standard specifies an optional OAMcommunication channel across the U-interface. If this channel isimplemented, ATU-C and ATU-R pairs may use it for transporting physicallayer OAM messages. Thus, the transceivers 122, 142 of such a systemshare various operational data maintained in their respective MIBs.

The DSL manager, controller, DSM Center, DSL optimizer, etc. may be anintegral part of an Access Node or DSLAM. The control function may beintegrated into a network element such as a DSLAM (for example in itscontrol processor) or may be in separate management element. The controlprocessor of the DSLAM may control several ‘smart’ modems.

Another interface for physical layer management is shown in FIG. 1B,which illustrates an augmented DSL system 102 that uses as a basis thepositioning diagram from the DSL Forum technical report TR-069. FIG. 1Bincludes one or more CPE side devices 110 that may be coupled to a CPEmodem or other DSL device 122 by a LAN 112. Modem 122 is coupled to aDSLAM or other upstream DSL device 130 by a twisted pair or othersuitable DSL connection 130. A DSL Manager 310/365 (for example, acontroller, DSL management entity, a DSL optimizer, a DSM Center,control software, etc.) is coupled to the DSLAM 142, for example throughthe Regional Broadband Network. The DSL Manager 310/365 may include asits components an Auto-Configuration-Server and a Service ConfigurationManager, and may have one or more “southbound” or downstream interfaces.In FIG. 1B, however, the southbound interfaces 132, 134 couple the DSLManager 310/365 to the CPE DSL device 122 and the DSLAM 142. Otherinterfaces according to embodiments of the present invention arepossible, as discussed in more detail below.

More information can be found regarding DSL NMSs in DSL Forum TechnicalReport TR-005, entitled “ADSL Network Element Management” from the ADSLForum, dated March 1998, which is well known to those skilled in theart. Also, as noted above, DSL Forum Technical Report TR-069, entitled“CPE WAN Management Protocol” dated May 2004 is well known to thoseskilled in the art. Finally, DSL Forum Technical Report TR-064, entitled“LAN-Side DSL CPE Configuration Specification” dated May 2004 is wellknown to those skilled in the art. These documents address differentsituations for CPE side management. More information about VDSL can befound in the ITU standard G.993.1 (sometimes called “VDSL1”) and the ITUstandard G.993.2 (sometimes called “VDSL2”), as well as several DSLForum working texts in progress, all of which are known to those skilledin the art. Additional information is available in the DSL Forum'sTechnical Report TR-057 (Formerly WT-068v5), entitled “VDSL NetworkElement Management” (February 2003) and Technical Report TR-065,entitled “FS-VDSL EMS to NMS Interface Functional Requirements” (March2004) and Technical Report TR-106 entitled “Data Model Template forTR-069 Enabled Devices,” as well as in the revisions of ITU standardG.997.1 for VDSL1 and VDSL2 MIB elements, or in the ATIS North AmericanDraft Dynamic Spectrum Management Technical Report, NIPP-NAI-2006-028R2.Further information may be found in the DSL Forum draft working textsWT-105 entitled “Testing & Interoperability: ADSL2/ADSL2plusFunctionality Test Plan” and WT-115 entitled “Testing &Interoperability: VDSL2 Functionality Test Plan” and WT-121 entitled“DSL Home Technical: TR-069 Implementation Guidelines” and DSL ForumTR-098 “DSLHome™ Gateway Device Version 1.1 Data Model for TR-069.”

As will be appreciated by those skilled in the art, at least some of theparameters described in these documents can be used in connection withembodiments of the present invention. Moreover, at least some of thesystem descriptions are likewise applicable to embodiments of thepresent invention. Various types of operational data available from aDSL NMS can be found therein; others may be known to those skilled inthe art.

In a typical topology of a DSL plant, in which a number of transceiverpairs are operating and/or available, part of each subscriber loop iscollocated with the loops of other users within a multi-pair binder (orbundle). After the pedestal, very close to the Customer PremisesEquipment (CPE), the loop takes the form of a drop wire and exits thebundle. Therefore, the subscriber loop traverses two differentenvironments. Part of the loop may be located inside a binder, where theloop is sometimes shielded from external electromagnetic interference,but is subject to crosstalk. After the pedestal, the drop wire is oftenunaffected by crosstalk because it is far from other active pairs formost of the drop, but transmission can also be more significantlyimpaired by electromagnetic interference because the drop wires areunshielded. Many drops have 2 to 8 twisted-pairs within them and insituations of multiple services to a home or bonding (multiplexing anddemultiplexing of a single service) of those lines, additionalsubstantial crosstalk can occur between these lines in the drop segment.

A generic, exemplary DSL deployment scenario in which embodiments of thepresent invention can be used is shown in FIG. 2. All the subscriberloops of a total of (L+M) users 291, 292 pass through at least onecommon binder. Though the loops in FIG. 2 are shown as approximately thesame length, it is more likely that the loops of a given system would beof varying lengths, and in some cases widely varying lengths. Each useris connected to a Central Office 210, 220 through a dedicated line.However, each subscriber loop may be passing through differentenvironments and mediums. In FIG. 2, L users 291 are connected to CO 210using a combination of optical fiber 213 and twisted copper pairs 217,which is commonly referred to as Fiber to the Cabinet (FTTCab) or Fiberto the Curb. Signals from transceivers 211 in CO 210 have their signalsconverted by optical line terminal 212 and optical network terminal 215in CO 210 and optical network unit (ONU) 218, which may also be referredto as a remote terminal (RT). Modems 216 in ONU 218 act as transceiversfor signals between the ONU 218 and users 291.

The loops 227 of the remaining M users 292 are copper twisted pairsonly, a scenario referred to as Fiber to the Exchange (FTTEx). Wheneverpossible and economically feasible, FTTCab is preferable to FTTEx, sincethis reduces the length of the copper part of the subscriber loop, andconsequently increases the achievable rates. The existence of FTTCabloops can create problems to FTTEx loops. Moreover, FTTCab is expectedto become an increasingly popular topology in the future. This type oftopology can lead to substantial crosstalk interference and may meanthat the lines of the various users have different data carrying andperformance capabilities due to the specific environment in which theyoperate. The topology can be such that fiber-fed “cabinet” lines andexchange lines can be mixed in the same binder. Users L+1 to L+M couldbe a Remote terminal (instead of CO) and the users 1 to L could be evencloser to customers, perhaps serviced by a line terminal or some otherfiber fed terminal (thus two fiber fed terminals with one closer tocustomers than the others). As can be seen in FIG. 2, the lines from CO220 to users 292 share the binder 222, which is not used by the linesbetween CO 210 and users 291. Moreover, another binder 240 is common toall of the lines to/from CO 210 and CO 220 and their respective users291, 292.

According to one embodiment of the present invention shown in FIG. 3A,an analyzer 300 may be part of an independent entity monitoring one ormore DSL systems as a controller 310 (for example, a DSL optimizer, adynamic spectrum manager or dynamic spectrum management center)assisting users and/or one or more system operators or providers inoptimizing or otherwise controlling their use of the system. (A dynamicspectrum manager may also be referred to as a Dynamic SpectrumManagement Center, DSM Center, DSL Optimizer, Spectrum MaintenanceCenter or SMC.) In some embodiments, the controller 310 may be operatedby an ILEC or CLEC operating DSL lines from a CO or other location. Inother embodiments, a “smart” modem unit can have a controller (having,for example, a processor and memory) integrated with the modem in a userlocation, a central office or some other single location. As seen fromthe dashed line 346 in FIG. 3A, controller 310 may be in or part of theCO 146 or may be external and independent of CO 146 and any partyoperating within the system. Moreover, controller 310 may be connectedto and/or controlling multiple COs. Likewise, components of controller310 may or may not be in the same location and/or equipment, and/or mayinstead be accessed by the controller at different locations.

In the exemplary system of FIG. 3A, the analyzer 300 includes collectingmeans 320 (which also may perform monitoring, if desired) and analyzingmeans 340. As seen in FIG. 3A, the collecting and/or monitoring means320 may be coupled to and may collect data through and from sourcesinternal to a DSL system, such as NMS 150, ME 144 at AN 140 and/or theMIB 148 maintained by ME 144. Data also may be collected from externalsources by means 320 through the broadband network 170 (for example, viathe TCP/IP protocol or other means outside the normal internal datacommunication systems within a given DSL system). Also, the collectingmeans 320 may have access to one or more databases or other sources 348,storing binder-level information, such as deployment information,topology information, crosstalk coupling, etc, or information aboutmodem capabilities, such as procedures for bit loading and powerallocation, and service priorities. The controller may collectoperational data from an ATU-R over the internet or even from an ATU-Cover the internet if the EMS bandwidth is limited or if the EMS isuncooperative (for example, by blocking reported management data becausethe equipment manufacturer wishes to perform the management internallyto its equipment). Operational data also can be collected from the NMSof the service provider, which may be collecting from various sourcesitself.

Analyzing means 340 and/or monitoring/collecting means 320 may also becoupled to a source 345 of margin-related parameter history and/or othersuch related information, such as a database or memory that may or maynot be part of the analyzer 300 or controller 310. One or more of theanalyzer's connections allows the analyzer 300 to collect operationaldata. Data may be collected once (for example, during a singletransceiver training) or over time. In some cases, the monitoring means320 will collect data on a periodic basis, though it also can collectdata on-demand or any other non-periodic basis, thus allowing theanalyzer 300 to update its user and line data, if desired.

The analyzing means 340 is capable of analyzing data provided to it todetermine whether instructions need to be sent to one or more modems toassist the modems in meeting a given margin target or in reducing thecrosstalk induced on modems of neighboring lines. The analyzing means340 of analyzer 300 is coupled to an instruction-signal generating means350 in the controller 310. Signal generator 350 is configured to accepta margin-related or power-related parameter value generated by theanalyzing means 340 for use by a modem, where the margin-related orpower-related parameter value is based on the operational data and iscalculated to assist at least one modem in meeting a margin target or inreducing induced crosstalk. Signal generator 350 is configured to sendinstruction signals (for example, a requested or required MAXNOMPSDvalue, PSDMASI setting or other instructions such as CARMASK, MAXSNRM,MINSNRM, TARSNRM, tone-dependent TARSNRM, MAXNOMATP, MAXRXPWR,tone-dependent BCAP, minimum/maximum net data rate, margin cap mode,service priorities or any of the rate-adaptive margins or timers) tousers in the communication system (for example, ADSL transceivers suchas ATU-Cs). As indicated by the dashed line 347, the instruction signalgenerating means 350 may or may not be part of the analyzer 300 and/orbe implemented in the same hardware, such as a computer system.Instruction signal generator 350 constitutes a means for regulating oneor more margin-related parameter values in the modem pair.

Another embodiment of the present invention is shown in FIG. 3B. A DSLoptimizer 365 operates on and/or in connection with a DSLAM 385 or otherDSL system component (for example, an RT, ONU/LT, etc.), either or bothof which may be on the premises 395 of a telecommunication company (a“telco”). The DSL optimizer 365 includes a data module 380, which cancollect, assemble, condition, manipulate and/or supply operational datafor and to the DSL optimizer 365. Module 380 can be implemented in oneor more computers such as PCs, workstations, or the like. Data frommodule 380 is supplied to a DSM server module 370 for analysis (forexample, determining the availability of profiles, transitions to beimplemented, etc. based on collected operational data for givencommunication lines, control and operational changes to thecommunication system, reported modem capabilities, etc.). Informationalso may be available from a library or database 375 that may be relatedor unrelated to the telco.

An operation selector 390 may be used to implement signals affectingoperation of the communication system. Such decisions may be made by theDSM server 370 or by any other suitable manner, as will be appreciatedby those skilled in the art. Operational modes selected by selector 390are implemented in the DSLAM 385 and/or any other appropriate DSL systemcomponent equipment. Such equipment may be coupled to DSL equipment suchas customer premises equipment 399. Device 385 can be used to implementany ordered changes based on allowable profiles, performanceenhancement, etc. considered by the DSL optimizer 365. The system ofFIG. 3B can operate in ways analogous to the system of FIG. 3A, as willbe appreciated by those skilled in the art, though differences areachievable while still implementing embodiments of the presentinvention.

The collecting means 320 or the data module 380 also may be coupled tothe corresponding modules of a second controller or DSL optimizer. Thus,operational data can be collected from other DSL lines, even when theyare not controlled by the same DSL optimizer, DSM center or SMC.Conversely, a controller 310 or DSL optimizer 365 may provideoperational data of its own DSL lines to a public or private database(for example, a public or privately controlled web site or connectionwhere DSL management entities can share data appropriately) forappropriate use by regulators, service providers and/or other DSLoptimizers.

As will be appreciated by those skilled in the art, if the controller isa wholly independent entity (that is, not owned and/or operated by thecompany owning and/or operating lines within the CO), much of the DSLsystem's configuration and operational information may be unavailable.Even in cases where a CLEC or ILEC operates and/or functions as thecontroller 310, much of this data may be unkown. Various techniques maybe used for estimating needed data and/or information. Examples of suchtechniques can be found in the following:

-   -   U.S. Ser. No. 10/817,128, entitled DSL SYSTEM ESTIMATION AND        PARAMETER RECOMMENDATION, filed Apr. 2, 2004;    -   U.S. Ser. No. 11/069,159, entitled DSL SYSTEM ESTIMATION        INCLUDING KNOWN DSL LINE SCANNING AND BAD SPLICE DETECTION        CAPABILITY, filed Mar. 1, 2005;    -   U.S. Ser. No. 11/122,365, entitled FEXT DETERMINATION SYSTEM,        filed May 5, 2005;    -   U.S. Ser. No. 11/342,024, entitled DSL SYSTEM ESTIMATION AND        CONTROL, filed Jan. 28, 2006;    -   U.S. Ser. No. 11/342,028, entitled BINDER IDENTIFICATION, filed        Jan. 28, 2006;        all of which are owned by Adaptive Spectrum and Signal        Alignment, Inc., and all of which are incorporated by reference        in their entireties for all purposes.

In some embodiments of the present invention, the analyzer 300 may beimplemented in a computer such as a PC, workstation or the like (oneexample of which is disclosed in connection with FIG. 8). The collectingmeans 320, analyzing means 340 and/or instructing signal generatingmeans 350 may be software modules, hardware modules or a combination ofboth, as will be appreciated by those skilled in the art. Thesecomponents may all reside in the same computer system, for example, ormay be in distinct apparatus. For management of large numbers of lines,databases may be introduced and used to manage the volume of datagenerated by the lines and the controller.

Generally, as shown in the example of FIG. 4, in a method 400 accordingto one embodiment of the present invention, a controller collectsoperational data (typically relating to the DSL modem pair of interest)at 410. The operational data may include historical margin performanceof the DSL system, historical performance data (such as previouslymeasured and known margin levels for the modem pair and otherperformance-related information), current performance data relating tothe DSL modem, retrain-count data, other data relating to training ofthe modem, or error data. The operational data may includeline/channel/data path performance monitoring parameters, line/channeltest parameters, diagnostics parameters, status parameters, linefailures and line inventory parameters.

The operational data may include an indication of the modem capabilitiesor of modem features or of modem configurations related to bit loadingand power allocation across tones. For some DSL modem implementations,the bit loading/power allocation algorithms used may be such that themargin per tone is at a very high level for certain tones/frequencies,but has a smaller value in other tones/frequencies. However, the averagereported margin will be dominated by the margin per tone with thesmallest value. Thus, the average reported margin may be found to besmaller than the maximum allowed margin (MAXSNRM), even though a largenumber of tones may actually have excessive margin values, and thereforeinduce excessive crosstalk. Other DSL modem implementations may use astricter interpretation of MAXSNRM and their algorithms may require thatthe MAXSNRM parameter should apply to the margin on any used tone. SuchDSL modem implementations have the advantage of minimizing the excesstransmitted power and induced crosstalk across all tones, and mayindicate this capability to a controller, DSL optimizer, DynamicSpectrum Manager, etc. in an appropriate way. Such capability is alsoreferred to as PREFBAND or margin cap mode “enabled.”

Other indications of modem capabilities may include the support of newservice priorities. Modems select their transceiver parameters based oncertain service requirements such as meeting a minimum net data rate, ormeeting a maximum delay, or meeting a minimum impulse noise protection.Traditionally, modems select their transceiver parameters with thefollowing priorities: first maximize net data rate, then minimize excess(average) margin with respect to MAXSNRM (as explained, for example, inITU-T recommendation G.993.2, VDSL2). Modems may choose to support analternative prioritization, such as first maximizing net data rate, thenminimizing excess margin per tone with respect to MAXSNRM. Otherprioritizations may include minimizing the delay, or maximizing theimpulse noise protection.

Such modem capabilities may be indicated to a far-end management entitythrough the use of the ITU-T recommendation G.994.1 (G.HS), also knownas “handshake.” A G.HS “code-point” may be assigned to indicate that amodem supports a certain capability. Alternately, an indication may becommunicated to a far-end management entity by an appropriate messageexchanged during DSL initialization (such as in the O-SIGNATURE or inthe R-MSG1 messages exchanged during “Channel Discovery” of the ITU-TRecommendation G.993.2, VDSL2). Such indications may be available to aDSM center, DSL optimizer, controller, etc. (for example, through anear-end or far-end management entity) which then can make use of suchindications in controlling one or more margin/power-related parametersof a DSL modem to assist with meeting a target margin and/or reducingthe induced crosstalk. The DSM center may also control modemcapabilities, in order to enable/disable modem features, processes,algorithms, etc.

In another embodiment of the present invention, the modem capabilitiesmay not be directly indicated to the controller, DSL optimizer, DSMcenter, etc., but it may be able to identify the modem type, which mightinclude information such as system vendor, chipset vendor, hardwarerevision, firmware version, serial number and others. Stored information(for example, look-up tables, etc.) about the modem capabilities ofvarious modem types may then be used by the DSM center in order to learnthe capabilities of a modem managed by the DSM center. Examples of suchtechniques can be found in U.S. Ser. No. 10/981,068, filed Nov. 4, 2004,entitled COMMUNICATION DEVICE IDENTIFICATION, which is owned by AdaptiveSpectrum and Signal Alignment, Inc., and which is incorporated byreference in its entirety for all purposes.

Data may be collected using the DSL system's internal communicationsystem(s) and/or using external communication (for example, theinternet). The operational data might include information regarding oneor more modem operational parameter values being used or set by themodem pair, which is collected at 420.

At 430 the controller analyzes the operational data to determine whatmargin-related parameter values might assist the modem pair in meeting amargin target or otherwise enhance performance of the modem pair. Thecontroller may then generate a margin-related parameter value at 440.The margin-related parameter value may be for a modem operationalparameter that the controller has considered or may be a differentmargin-related parameter. At 450 the controller generates an instructionsignal representing the margin-related parameter value and sends that toat least one modem in the modem pair, thus instructing the modem pair toadopt the margin-related parameter value for use in training or innormal operation, depending on the circumstances. A margin-relatedparameter may include parameters for line configuration and parametersfor channel configuration as defined in the ITU-T G.997.1 (G.PLOAM)recommendation. The margin-related parameter may also include controlsas defined in the draft ATIS Dynamic Spectrum Management Technicalreport, NIPP-NAI-028R2. Finally, the margin-related parameter mayinclude controls such as target SNR margin per tone, bit-cap per tone,margin cap mode, PREFBAND and others.

Another embodiment of the present invention is shown in FIG. 5. Method500 begins with a first DSL system operating using a first profile as acurrent profile at 510. Operational data is then collected at 520 (forexample, by a controller or the like). The operational data can beoperational data pertaining to operation of the first DSL line/system,but also can include operational data collected from one or moreneighboring DSL systems (that is, DSL systems in close physicalproximity to the first DSL system). Operational data collected at 520may be similar as those collected at 410 and 420. Also, binder-levelinformation is collected at 530. The binder-level information, asdiscussed in more detail below, can be deployment information, topologyinformation, crosstalk coupling information and/or any otherbinder-level information that might assist in evaluating performanceoptions and evaluating alternative profiles. This binder-levelinformation can be actual data about binder structure and environmentand/or assumed information for use in any spectrum balancing method thatmight be used in connection with method 500. Such spectrum balancingmethods can compute or otherwise generate allowed profiles comprisingconfiguration parameter values. A second profile is selected at 540 as asecond profile. The second profile can be selected from one or moreprofiles designed and/or selected at 525, which design/selection cantake place at any appropriate time and be updated, if desired. Thissecond profile can be chosen from profiles that are allowable based onthe collected binder-level information.

At 525 profiles as well as transition matrices, transition rules anddata weightings can be designed and/or selected. Design/selection at 525may tale into account collected operational data such as indications ofmodem capabilities and/or modem features. An indication that a modem iscomplying with a requirement to keep the SNR margin per tone smallerthan the maximum SNR margin (known as PREFBAND, or margin cap mode), oran indication that a modem is using different service priorities fordetermining transceiver parameters such as bi, gi, FEC parameters,interleaving parameters and others can be advantageously exploited by aDSM center to determine one or more appropriate profiles.

As an example, a modem reporting or indicating a PREFBAND (or margin capmode) capability is assured to minimize its excess margin relative to aMAXSNRM requirement. A modem reporting no such capability would besuspect of transmitting excessive power, and thus causing excessivecrosstalk. According to one embodiment of the present invention,profiles are designed differently depending on the PREFBAND (or margincap mode) indication. When PREFBAND is on, then the profiles make use ofthe MAXSNRM parameter:

Profile 1:

-   -   MAXSNRM=16 dB    -   Minimum rate=1.5 Mbps, Maximum rate=3.0 Mbps

Profile 2:

-   -   MAXSNRM=16 dB    -   Minimum rate=3.0 Mbps, Maximum rate=6.0 Mbps        In this case, it is assured that Profile 1 is consuming less        power compared to Profile 2.

When PREFBAND is off, then the profiles must make use of otherparameters to control the transmitted power, such as the MAXNOMPSD(maximum nominal PSD) parameter:

Profile 1:

-   -   MAXNOMPSD=−52 dBm/Hz    -   Minimum rate=1.5 Mbps, Maximum rate=3.0 Mbps

Profile 2:

-   -   MAXNOMPSD=−40 dBm/Hz    -   Minimum rate=1.5 Mbps, Maximum rate=3.0 Mbps        In this case, the transmitted nominal PSD is forced to a smaller        value in profile 1 to reduce crosstalk emissions.        At 550 the operability of the proposed/second profile is        evaluated based on the collected operational data (including any        profile transition rules) to determine whether the proposed        profile is available from that standpoint. If the proposed        profile is available after evaluation at 550, then at 560 the        first DSL system is instructed to change configuration and/or        operation to use the proposed profile. In cases where multiple        DSL systems are under evaluation, the instructions at 560 might        be to the first DSL system and/or one or more neighboring DSL        systems, thus allowing mutually beneficial updating of operation        of multiple users' systems. For example, another service        provider's controller, DSL optimizer, etc. might be present (for        instance, both could be customers of a management firm or other        entity) and thus know what neighboring DSL systems are doing.        This knowledge might allow each controller, DSL optimizer, etc.        to benefit even though they do not otherwise correspond. After        560, the controller may return to 540 to select another proposed        profile, or it may return to 510 to operate the line with the        current profile.

The controller may update operation of the modem pair and/orconfiguration of the DSL system (for example, a DSL line or loop) byperforming such an analysis more than once, as shown by the dottedarrows in FIGS. 4 and 5, or may do it only at specified times, such asimmediately before modem training. As will be discussed in detail below,the parameters with which the controller works and operational dataavailable to the controller varies, depending on the type of DSL systemin which the modem pair operates. Again, the modem operationalparameter(s) used by the controller in analyzing the modem marginperformance may or may not be the same parameter as that for which themargin-related parameter value is generated and sent to the modem. Whilenot limited to such types, embodiments of the present invention arehelpful in assisting modems employing ADSL1, ADSL2, ADSL2+, VDSL1 and/orVDSL2. Use of the controller may assist in making sure thatstandards-compliant modems remain compliant. Moreover, embodiments ofthe present invention can be used to enhance performance of one or moreDSL lines by taking into account operational data, binder-levelinformation like crosstalk effects and other information that can have adeleterious effect on DSL performance.

Basically, a new profile may include one or more of the spectrum level,power, spectrum shape, etc. that can be changed in response to reportedmargin and performance history. That is, after evaluating data aboutprior performance of a modem pair, and knowing one or more of the modempair's profile, margin-related parameters, etc., a controller or thelike can suggest or force a modem or modem pair to adopt a new profileand/or operational values that will assist the modems in meeting one ormore margin targets, and in possibly reducing the induced crosstalk.

In some embodiments of the present invention, a controller coupled tothe ATU-C side of a modem pair dynamically controls profiles, marginsettings and adjustments for each line (for example, in an ADSL2 system,by setting and/or changing the MAXSNRM parameter, by imposing adifferent MAXNOMPSD level, or by setting the PSDMASK in an ADSL2+ modemor by combinations of some or all of these, or some of the otherparameters previously mentioned such as CARMASK, MAXSNRM, TARSNRM,MINSNRM, RA-margins/timers). In other embodiments, the controller maydetermine from a history of reported margin and/or other measurementsthat the line is exceeding a desired margin target and thereby impose aprofile having a lower PSD level during or before training by themechanisms discussed above. Similarly, if for some reason a modem is notusing sufficient power and/or margin and is experiencing excessive noiseand error problems, the controller can instruct the modem to use aprofile having a higher PSD level during training or operation to permitbetter operation.

As noted above, it may be preferable in some systems to use ahistorical, previously measured and/or known margin to “seed” thetraining process so that an appropriate power reduction is implementedduring training. The controller can maintain or have access to aperformance history, thus continuously allowing the controller toimprove estimates and decisions concerning what PSD or othermargin-related parameters to instruct the modem to use when the modem isreset or retrains (which can be forced or recommended, if appropriate).For example, a service provider or controller may wait until the line isinactive—for example, counting ATM cells or other customerinformation-passing measures to know when the line is active or not—andthen reset to use the newer PSD(s) in a manner completely transparent toa user. In other situations, the service provider may simply retrain ata time when the system is very unlikely to be in use (for example, inthe middle of the night). In some embodiments, the controller can usethis historical information, telling the one or both of the modems inthe modem pair (for example, the ATU-C) what initial PSD level should beused so that an available PCB value or other adjustment (for example, a−14.5 dB drop by the ATU-R) has a chance of meeting the marginspecification.

In some embodiments of the present invention, programming is based oneither previous use(s) or training. The previous uses may be moreimportant in some cases. A second pass through training, which also canbe used, essentially is a quick fix for the modem vendors themselves,particularly for downstream transmission with the DSLAM vendors, wherethe modems can essentially stop the current training and then commencetraining from the beginning a second time with a different, lower NOMPSDthat causes the margin then to be less than MAXSNRM. Afrequency-dependent bit-cap or frequency-dependent target margin ornoise (as described in T1E1.4/1992-203) also could be imposed by thecontroller on a second training to ensure the MAXSNRM was observed.

Several techniques are known to those skilled in the art for selectingthe DSL configuration of multiple lines, when those lines causesignificant crosstalk into each other. In such cases, DSL configurationparameters such as minimum/maximum data rate, minimum/target/maximummargin, PSD mask, carrier mask, maximum aggregate transmitted power,maximum received power and the like can be used to optimize theperformance of the multiple lines subject to desired requirements forthe DSL configuration (for example minimum data rate and margin) andsubject to certain configuration constraints (for example the maximumaggregate transmitted power supported by the DSL system).

Known spectrum balancing methods and techniques include Optimum SpectrumBalancing, Iterative Spectrum Balancing, SCALE, C-NRIA and the BandPreference Algorithm. Optimum Spectrum Balancing can be found in variouscontributions to the T1E1.4 Working Group of ATIS, includingContributions T1E1.4/2003/325, T1E1.4/2004/459 and T1E1.4/2004/460, andin “Optimal Multiuser Spectrum Management for Digital Subscriber Lines,”Proc. of the IEEE International Conference on Communications, ICC, pp.1-5, Paris, France, June 2004. Iterative Spectrum Balancing can be foundin “Low complexity near optimal spectrum balancing for digitalsubscriber lines,” IEEE International Conf. on Communications. (ICC),Seoul, Korea, 2005, and in “Iterative Spectrum Balancing for DigitalSubscriber Lines,” IEEE International Communications Conference (ICC),Seoul, May, 2005. SCALE can be found in “Low-Complexity DistributedAlgorithms for Spectrum Balancing in Multi-User DSL Networks”, IEEEInternational Conference on Communications, Istanbul, Turkey, June 2006.C-NRIA can be found in “The Constrained Normalized-Rate IterativeAlgorithm,” 1st Conference on Computers, Communications, and SignalProcessing, Kuala Lumpur, Malaysia, November 2005. Finally, the BandPreference Algorithm can be found in Section 15.4 in Chapter 15 of thecourse notes for Stanford University course EE479 Multiuser DigitalTransmission Systems, taught at Stanford University in Fall 2005. Thoseskilled in the art know how to select and implement any requiredspectrum balancing method for use in connection with embodiments of thepresent invention.

Embodiments of the present invention overcome practical difficultiespreviously associated with using the above techniques in practical DSLsystems deployed in the field. One of the main challenges in using somethe above algorithms has been that they require a large amount ofcomputation to be performed in determining transmit power spectraldensities for the multiple DSL systems that achieve reduced crosstalknoise and improved performance. More importantly, DSL systemenvironments are not static, so transmit power spectral densities needto be updated periodically to account for interferer and/or channelvariations. Thus, computational requirements can easily becomeunmanageable, especially when jointly optimizing a large number of DSLsystems.

Another earlier shortcoming overcome by embodiments of the presentinvention is that many of the above algorithms require the collection ofparameters that might not be available from the DSL systems, or mightnot be within a single management system's control. For example,crosstalk information (designated as Xlog by those skilled in the art,as explained in the ATIS draft technical report on Dynamic SpectrumManagement, contribution NIPP-NAI-028R2) may not be reported or computedby all DSL systems. Topological information about the location of a CO220 relative to an ONU/RT 218 (for example, as seen in FIG. 2) may alsobe unavailable. Even when parameters such as channel gains per tone,noise per tone, crosstalk coupling per tone, maximum transmitted power,and the like are available, dynamically ascertaining the configurationof the DSL systems by determining the bits and gains tables (asdescribed by some of the above algorithms) in a controller 310 andcommunicating the results to an access node 140 requires significantcommunication, especially when results require frequent updating.

Finally, embodiments of the present invention eliminate the requirementthat such algorithms be executed in a centralized fashion, wherein theconfiguration of the DSL systems is jointly determined. This centralizedapproach requires that the controller 310 collects information for allmanaged DSL lines, determines configuration parameters such as transmitpower spectral density jointly for all managed lines, and sets theconfiguration parameters of those managed lines at approximately thesame time. There are significant obstacles to adopting this centralizedapproach, for example regulatory and operational issues. Considering theexample of FIG. 2, CO 220 and DSL lines 227 frequently are managed by adifferent entity than the entity managing CO 210 and DSL lines 217. Suchsituations typically emerge either because multiple companies controlthe DSL loops or because the same company segregates its own lines intodifferent management systems.

Embodiments of the present invention adaptively change the configurationof one or more DSL lines, which may include parameters such as themaximum nominal power spectral density (MAXNOMPSD), the maximum nominalaggregate transmit power (MAXNOMATP), the level of power cutback (PCB),the fine gains (gi), the transmit spectral scaling (tssi), the powerspectral density mask (PSDMASK), the power spectral density level (PSDlevel), the maximum received power (MAXRXPWR), the upstream power“back-off” (UPBO) configuration, the carrier mask (CARMASK), the minimumimpulse noise protection (INP), the maximum delay (DELAY), the targetmargin (TARSNRM), the minimum margin (MINSNRM), the maximum margin(MAXSNRM), the preference band indication (PREFBAND), the margin capmode, the target data rate, the minimum data rate, the maximum datarate, the FEC and interleaving parameters, the per tone bit cap(BCAP[n]), the per tone target SNR margin (TSNRM[n]) and the referencenoise (REFNOISE). The above parameters (and possibly others well knownto those skilled in the art) are elsewhere described in this applicationas “margin-dependent” or “margin-related” parameters. A specificconfiguration of a given DSL line (which can include one or more of theabove-listed control parameters) is often collectively called a DSL line“profile,” which term has been used accordingly herein and which is wellunderstood by those skilled in the art.

Embodiments of the present invention adaptively change the profiles ofone or more DSL lines to reduce crosstalk noise and to improve DSLperformance. A DSL line using a specified profile also can be said to bein a “state,” as is well known to those skilled in the art. Embodimentsof the present invention control the transition of one or more DSL linesbetween profiles or states. The transitions are performed by evaluatingthe current state of the line relative to one or more target states. Thepossible target states (also referred to herein as proposed or targetprofiles, or “second” profiles) for a given current state (that is, a“first” profile) of a DSL line are defined through transition matrices.Such transition matrices may include prioritization of the target statesfor a given current state. Evaluation of the feasibility of staying inthe current state or moving to one of the target states can be based ondistributions of reported and estimated data distilled from operationaldata collected from the DSL system. Detailed descriptions of methods andsystems for controlling profile transitions in DSL systems are given inU.S. Serial No. U.S. Ser. No. 11/071,762, entitled DSL STATE AND LINEPROFILE CONTROL, filed Mar. 3, 2005, owned by Adaptive Spectrum andSignal Alignment, Inc., which is incorporated by reference in itsentirety for all purposes. The description herein discloses one or moreexamples of how profiles, transition matrices and transition rules canbe designed to allow DSL lines to achieve reduced crosstalk and improvedperformance.

Embodiments of the present invention can utilize, for example, a statediagram 600 as illustrated in FIG. 6, where 8 profiles 602-1, 602-2,602-3, 602-4, 602-5, 602-6, 602-7 and 602-8 are profiles in which a DSLline may operate. In this example each profile is defined by a maximumattainable data rate (192, 384, 768 or 1536 Kbps) and a latency (“Fast”meaning no interleaving; “H delay” meaning interleaving producing a highdelay).

In FIG. 6, if a line is operating using profile 1, then from both thestate diagram and the state-transition matrix T1 (where a 0 means thatstate is not available), it can be seen that profiles 1, 2, 5 and 6 arepossible transitions (remaining in profile 1 is not a transition insense of a change, but for ease of reference, remaining in the sameprofile may nevertheless be referred to as a “transition” herein).However, the state-transition matrix T1 does not indicate whichtransition, if any, should have priority above other transitions.Therefore, the change to matrix T2 of FIG. 6 can be made, where priorityis specified by an integer value. The higher the positive integer value,the less attractive the designated profile is for service providerimplementation.

In transition matrix T2, 0 still means that the transition is notallowed, and any positive integer means that the transition is allowed.The lowest positive integer has the highest priority above any othertransition. For instance, a line in profile 1 will try to move toprofile 2 if possible (that is, the priority is 1 from matrix T2). Ifprofile 2 is not appropriate (for example, if the code violations areexpected or measured to be too high in profile 2, “appropriateness” canbe defined in some embodiments as feasibility as discussed in moredetail below), then the line will attempt a move to profile 6 (that is,having a priority of 2 from matrix T2). If profile 6 is not appropriate,then profile 1 (having a priority of 3) will be examined and the profilewould not be changed, if profile 1 is appropriate. If profile 1 also isnot appropriate, then the line will move to profile 5, which has thelowest priority (that is, a priority of 4).

Transition matrix T2 of FIG. 6 can thus indicate both the possibilityand the priority of transitions for each state/profile. The structure ofT2 enables simple variation of many different profile characteristicssuch as data rate, power level, flat power-spectral-density (PSD)reference level, maximum margin, minimum margin, target margin, FECdelay, FEC strength and PSD shaping (sometimes known as PSDMASK). Forinstance, depending on a set of specific permitted service types, someprofiles can be blocked, while other profiles are given lowerpriorities. Alternatively, profiles with smaller carrier masks can begiven higher priorities for the customers who pay accordingly (whereeconomic factors are taken into consideration by the operator). Variouslines can be thus programmed to yield part of the band whenever possibleto enable better service on other lines (not taking into accountregulatory implications of such polite binder sharing, which may bepossible in some cases and not in others). As another example, profileswith higher target margins (for example, TARSNRM or TNMR) can be givenhigher priorities for a line that has frequent changes in noiselevel(s). The weighted state-transition matrix T2 thus allows dynamicchange of the rules for profile selection as well as the dynamicselection of profile itself. The profile selection may also include aband-preference indication (or margin cap mode) that indicates preferredinterpretation of the parameters for subsequent modem-loading operation.

In some embodiments of the present invention, an overall rule may simplybe a function whose inputs are the results from a group of sub-rules andwhose output is either “yes” or “no” to the transition from n to m. Inone embodiment, an overall rule can be called only if a minimum new datarequirement is satisfied. Such a rule, one example of which isillustrated in FIG. 7, can be composed of two parts, a “good behavior”qualification and a “bad behavior” qualification (that is, showing asufficient absence of bad behavior), where a transition to state m isallowed only if both qualifications are satisfied. Using sub-rules asnoted above, many of the outputs do not have to be used in the overallrule of FIG. 7. The sub-rules can represent a general structure whendata rate, margin, code violation and retraining are of concern, andchanges to the overall rule might utilize any sub-combination of thesub-rules, as will be appreciated by those skilled in the art. In theexample of FIG. 7, the sub-rules are denoted as follows: RRDC isreported rate distribution, ERDC is estimated rate distribution, RCVDCis reported code violations distribution, ECVDC is estimated codeviolations distribution, RMDC is reported margin distribution, EMDC isestimated margin distribution, RNRDC is reported retrain distribution,ENRDC is estimated retrain distribution.

The first part (the good behavior qualification) says that at least somesub-rules must report “GOOD” for a transition to be allowed. Therequirement may consist of the following three conditions:

-   -   Good behavior for rate in either current state (“reported”) or        target state (“estimated”);    -   Good behavior for code violation in either current state or        target state; and    -   Good behavior for number of retrains in either current state or        target state. Good-margin behavior is not included since        good-rate behavior has a similar implication.

The second part (the bad behavior qualification) says that bad behaviorshould not be expected in a target state. As will be appreciated bythose skilled in the art, the definition of bad behavior can differdepending on whether the state is moving down or up. When moving down,the performance in current state n serves as the lower limit of expectedperformance in the target state. When moving up, the performance in thecurrent state serves as the upper limit of expected performance in thetarget state. Therefore the rules are slightly different wheneversub-rules related to the current state are involved. When the transitionis neither moving up nor down, then a conservative decision is made byassuming it is moving up.

In some embodiments of the present invention, the method 800 of FIG. 8can be used. Method 800 commences with the construction 810 (and/orimplementation or programming) of the T matrix (or any otherstate-transition control mechanism), threshold tables (or the like), anyrules and/or sub-rules governing transitions, and any rules for purging,discounting or otherwise weighting old data. A “current profile” orstate n is selected and operation begins using this profile at 820.Operational data is collected at 830 and any old data available ispurged and/or discounted as appropriate (for example, by using a dataweighting vector W). Method 800 then verifies that there is sufficientnew data (for example, both reported data and estimated data) at 840 topermit evaluation of the infeasibility of any target state (using therule that any state is presumed feasible until proven otherwise). Ifsufficient new data is not available, then the method returns to datacollection at 830.

If sufficient new data has been assembled, then feasibility tests can berun at 850 for all potential target states m to determine whether anycan be disqualified. The feasibility (infeasibility) tests performed at850 may take into account collected operational data such as indicationsof modem capabilities or modem features. Once the eligible target stateshave been identified, the system may move at 860 to the highest prioritystate available. The system then can update transition rules and data at870, such as a T matrix, threshold tables, data weighting rules/vectors,etc. and return to data collection at 830 for the next transitionevaluation.

Various levels of information may be available for an individual line onwhich the design of profiles, transition matrices and transition rulescan be based. Such designs may depend on the amount of “binder-levelinformation” that is available to the individual line. The binder-levelinformation can include (but is not necessarily limited to) and becategorized as:

-   -   Deployment information—In this case, binder-level information        includes the characterization of a DSL line as being deployed        from a CO, an RT, the SAI, and/or other points within the local        loop topology. No information is available about distances        between the CO, the RT, the SAI, or other points, or about the        crosstalk coupling strength between lines.    -   Topology information—In addition to deployment information,        topological information about the relative location of CO, RT,        SAI or other deployment points may be available. Such        information can comprise location information of such deployment        points or approximate distances between such deployment points.        Information about the neighborhood that the DSL line reaches may        also be available. Neighborhood information may comprise an        indication that lines in the neighborhood that the DSL line        reaches are affected by certain kinds of noise sources (e.g.        HDSL, SHDSL, radio-frequency interference). No information about        crosstalk coupling strength between specified lines is        available. Bridged-tap presence, location and length information        may or may not be available.    -   Crosstalk coupling information—In addition to deployment and        topology information, this case includes information about        crosstalk interaction between DSL lines. Such crosstalk        interaction information may comprise crosstalk coupling        parameters, crosstalk strength characterization, crosstalk        noise, etc.

Such binder-level information can be collected using collecting means320 from an appropriate source (for example, a CO 146, source 348, etc.as shown, for example, in FIG. 3A). The DSM Technical Report defines theXlin and Xlog parameters as containing crosstalk coupling information.Xlin denotes the insertion loss function representing the crosstalkcoupling between a first disturbing DSL line and a second disturbed DSLline. Xlog denotes the logarithmic magnitude of Xlin. Also, databasesare maintained by DSL service providers/network operators that maycontain deployment information and/or topology information. Suchdatabases are part of Operations Support Systems (OSS), and may be knownas wire-map databases. In some embodiments of the present invention, thebinder-level information can be estimated using the analyzer 300 of acontroller 310 as shown in FIG. 3A. As one example, methods and systemsdescribed in U.S. Ser. No. 11/342,028, referenced above, can be used toextract information about a binder from collected DSL operational data,though other such methods and/or systems are known to those skilled inthe art.

When only deployment information is available, then different profiles,transition matrices and transition rules may be used for each linedepending on the deployment point of the line. For a deployment pointsuch as an RT, which typically lies closer to the customer premises andfor which higher frequencies can be used reliably for downstream DSLtransmission, the profiles can include profiles that restrict the use oflower frequencies in the downstream direction. For example, profiles forwhich lower downstream frequencies are completely disabled, or profilesfor which the downstream PSD mask at lower frequencies is lower than thedownstream PSD mask at higher frequencies may be used. For a deploymentpoint such as a CO, which typically lies farther from the customerpremises and in which lower frequencies can be used more effectively fordownstream DSL transmission, the profiles can include profiles thatrestrict the use of higher frequencies, and allow higher transmittedpower levels in the lower frequencies. Such control of power usage canbe achieved by configuring parameters such as PSDMASK, CARMASK, MAXSNRM,TARSNRM, BANDPREF, MAXNOMPSD, MAXNOMATP, MAXRXPWR, DPBOSHAPED(Downstream Power Back-Off Shaped), UPBOSHAPED (Upstream Power Back-OffShaped), margin cap mode and the like (some of which are defined incurrent amendments to G.997.1), in either the downstream or the upstreamdirection.

In an example of one embodiment of a method for ADSL service operatingfrom an RT, in the absence of more detailed information, the design ofprofiles for the RT (for example, at 525 of FIG. 5) can be based on aworst-case analysis with respect to the strength of crosstalkexperienced by DSL receivers of CO-based DSL lines, and which is inducedby DSL transmissions from the RT. Using either theoretical models orfield data, a number of scenarios can be simulated with increasinglystronger crosstalk situations. For example, a mild crosstalk situationwould be with a CO line of 12kft and an RT line of 10kft, where the RTis located 2kft from the CO. A strong crosstalk situation would be witha CO line of 12kft and an RT line of 4kft, where the RT is located 8kftfrom the CO. For each such scenario, a suitable spectrum managementmethod (for example, OSB, ISB, SCALE, C-NRIA, band preference methodsthat are known to those skilled in the art) can be used to derive bysimulation an RT profile with the desired data rate range and reducedcrosstalk. The simulation may be repeated for various desired data ratepoints to obtain a number of possible (that is, allowed or allowable)profiles. Thus, a group of RT profiles can be designed corresponding toincreasingly stronger crosstalk conditions. A similar procedure can befollowed to design profiles for DSL services operating from otherlocations (for example, a CO).

Thus, profiles can be designed for DSL services either at the CO or atthe RT. The transition matrices for these profiles can be designed witha higher priority on desired characteristics (for example, profiles thatminimize frequency usage, minimize transmitted power, minimize inducedcrosstalk, etc.). A set of narrow range rate-adaptive profiles may alsobe used, allowing the DSL manager (controller, DSL optimizer, SMC, DSMCenter, etc.) to choose a lower target margin and a range of data-rateoperation for the line that leads to lower retrain rates, lowercustomer-churn possibility, and/or lower maintenance actions/costs aswell as increasing the average rate/range footprint for the serviceprovider. Such operation is sometimes called “Tiered Rate Adaptation” orTRA. The transition rules (or thresholds) can be based on a variety ofcriteria, as noted in U.S. Ser. No. 11/071,762, referenced above. Thetransition rules can be designed so that, if the DSL line operatesreliably in a current state/profile, and if the DSL line also is likelyto operate reliably in a state/profile that might reduce crosstalk, thenthe DSL line state/profile should be changed to the state/profile thatshould reduce crosstalk. An example of such profiles, transitionmatrices and transition rules is shown in FIG. 9. Transition rules maybe adapted to the line and the desired acceptable probability ofcustomer dissatisfaction in the form of churn rates, trouble calls,truck rolls, etc.

The system/method of FIG. 9 has 3 profiles 910, 920, 930 available (thatis, allowable profiles). In profile 910 all frequencies are allowed(usable); in profile 920 only frequencies above 400 kHz are allowed; andin profile 930 only frequencies above 800 kHz are allowed. Transitionsare allowed as follows:

-   -   940, 942—between profile 910 and profile 920; and    -   950, 952—between profile 920 and profile 930.        Transitions can be restricted to being performed only when        specified conditions are met. Examples of these types of        conditions follow (where CV stands for code violations in DSL        operation):    -   942—Profile 1 to Profile 2—CV=0 for 99% of time, rate at profile        1≧target rate for 99% of time, estimated rate at profile        2≧target rate    -   940—Profile 2 to Profile 1—CV>10 for 5% of time, rate at profile        2<target rate for 5% of time, estimated rate at profile 1≧target        rate    -   952—Profile 2 to Profile 3—CV=0 for 99% of time, rate at profile        2≧target rate for 99% of time, estimated rate at profile        3≧target rate    -   950—Profile 3 to Profile 2—CV>10 for 5% of time, rate at profile        3<target rate for 5% of time, estimated rate at profile 2≧target        rate

When topology information also is available, the above-describedtechniques for identifying and using profiles, transition matrices andtransition rules can be enhanced to take into account such information.The same principles identified above—placing more emphasis on the higherfrequencies for downstream DSL transmission from the RT point andplacing more emphasis on the lower frequencies for downstream DSLtransmission from the CO point—can still be applied, but the additionaldistance and loop length information available in topology informationcan help to improve profiles by using real conditions rather thanassumed worst-case conditions. Also, for upstream DSL transmission (forexample, for VDSL1 and VDSL2), profiles with different upstream powerback-off or power spectral density, possibly with band preference (ormargin cap mode) on or off, configurations can be used depending ontopological knowledge such as the length of neighboring loops.

When topology information is available as all or part of thebinder-level information, DSL system configurations for ADSL serviceoperating from the RT and having knowledge of the loop topology can beimplemented using embodiments of the present invention. The selectionand/or computation of profiles allowed for use with a given DSL system(for example, at 525 of FIG. 5) can still be based on an analysisregarding the strength of crosstalk experienced by the DSL receivers ofCO-based DSL lines, and induced by DSL transmissions from the RT. Butthe loop topology knowledge allows the analysis to be performed for theknown parameters of loop length and distance between CO and RT.Simulation is still performed for various scenarios that progressivelyassume stronger crosstalk coupling (for example, 50% worst-casecrosstalk, 90% worst-case crosstalk, 99% worst-case crosstalk). For eachsuch scenario, one of the previously mentioned spectrum managementmethods (OSB, ISB, SCALE, C-NRIA, band preference method) can be used toderive by simulation an RT profile with the desired data rate range andreduced crosstalk. The simulation may be repeated for various desireddata rate points to obtain a number of allowable profiles. Thus, a groupof RT-based profiles is designed corresponding to increasingly strongercrosstalk conditions. A group of CO profiles can be designed in the samemanner. Consequently, transition matrices and transition rules can beintroduced in a way similar to the case where only deploymentinformation is available.

When topology information is available as all or part of thebinder-level information, DSL system configurations for VDSL servicewith UPBO and again having knowledge of the loop topology can beimplemented using embodiments of the present invention. Knowing the looptopology again allows simulation of a number of scenarios withprogressively stronger crosstalk coupling in designing/selectingallowable profiles (for example, at 525 of FIG. 5). The result ofsimulation is a corresponding profile for each scenario for theapplication of upstream power back-off. Such back-off may be applied bycontrolling the reference PSD, PSDREF, the electrical length, UPBOKLE,the constants a and b of the known UPBO algorithm, or by controllingPSDMASK and CARMASK. This group of profiles can then be used inconjunction with transition matrices and transition rules to reduceupstream FEXT in VDSL. The transition matrices are designed with higherpriority placed on profiles that achieve more aggressive powerreductions. The transition rules are designed so that a transition to aprofile with more aggressive power reduction is allowed only if thecurrent DSL line state exhibits an adequate level of stability and if itis estimated that the transition will not cause the DSL line performanceto fall below a minimum acceptable level.

When crosstalk-coupling information is also available, the design ofprofiles, transition matrices and transition rules can take into accountsuch information. In such a case, the configuration parameters relatedto power controls can be obtained by executing a simulation under theknown conditions. One of the previously mentioned spectrum balancingmethods (OSB, ISB, SCALE, C-NRIA, band preference method) can be used toderive by simulation the RT or CO profile with the desired data raterange that achieves reduced crosstalk on neighboring pairs. Thesimulation can be performed for various desired data rate points toobtain multiple possible profiles, including the use of differentloading algorithms by the various modems in the binder depending onwhether band preference (also known as margin cap mode) is on or off.This methodology can be applied for determining the parameters of thedownstream and/or the upstream transmission. Thus, a group of profilesis designed corresponding to different data rate points, but optimizedfor the specific loop and crosstalk conditions.

When crosstalk-coupling information is also available, the design oftransition matrices and transition rules can be performed in a waysimilar to the case where only topology information is available.Transition rules can be further enhanced so that they include rules forcollected parameters (collected operational data) from lines in the sameneighborhood (that is, lines in close physical proximity) as the lineunder consideration for a transition. For example, a transition rule forincreasing the data rate of a line may require that the data rate of aneighboring line exceeds a certain threshold for some percentage of thetotal observation time.

In another embodiment of the present invention, “tiered rate adaptive”(TRA) profiles can be designed for DSL services. A profile typicallyincludes the configuration parameters of minimum net data rate andmaximum net data rate. An example of a set of TRA profiles is shown inFIG. 10, where TRA profiles 1012, 1014, 1016 use gradually higher datarate windows 1013, 1015, 1017, respectively, to achieve higher profileminimum net data rate and profile maximum net data rate settings thatare within the allowed and/or achievable minimum data rate 1004 andmaximum data rate 1006. Thus, the combination of the set of TRA profilescovers the entire data rate range which would otherwise be covered by asingle rate adaptive profile with a minimum net data rate 1004 and amaximum net data rate 1006. The minimum net data rate over all the TRAprofiles is equal to the minimum net data rate of the otherwise usedrate adaptive profile, and the maximum net data rate over all the TRAprofiles is equal to the maximum net data rate of the otherwise usedrate adaptive profile. The combined use of the TRA profiles allows a netdata rate range that covers the data rate range between the minimum netdata rate and the maximum net data rate of an otherwise used rateadaptive profile. The example of FIG. 10 shows 3 TRA profiles, however,other embodiments can use a different number of TRA profiles. TRAprofiles typically use the same target SNR margin (TARSNRM), though arenot required to do so. Such TRA profiles with a constrained range forminimum and maximum net data rate have significant advantages comparedto a single rate-adaptive (RA) profile that has a wide net data ratevariation. If a DSL line using an RA profile trains during a time withweak noise conditions, then it has a high risk of retrain at a latertime if the noise becomes stronger. On the other hand, such retrains canbe prevented if the appropriate TRA profile is used, so that the maximumnet data rate of the TRA profile does not exceed the attainable maximumnet data rate 1006 at any time. Using the process shown in FIG. 5, theappropriate TRA profile 1012, 1014, 1016 can be selected based oncurrent and estimated rate distribution data.

If a single RA profile is used with a high target SNR margin, then anoise increase can trigger a retrain that can leave the line in a statewith a very low rate. This also is prevented by the TRA profiles,because the maximum net data rate is constrained, while the target SNRmargin can still be allowed to have a relatively small value. TRAprofiles have advantages over RA profiles in that they can lead to lowerretrain rates, lower customer-churn possibility, lower maintenanceactions/costs, etc. They also can increase the average rate/rangefootprint for the service provider.

Generally, embodiments of the present invention employ various processesinvolving data stored in or transferred through one or more modemsand/or computer systems. Embodiments of the present invention alsorelate to a hardware device or other apparatus for performing theseoperations. This apparatus may be specially constructed for the requiredpurposes, or it may be a general-purpose computer selectively activatedor reconfigured by a computer program and/or data structure stored inthe computer. The processes presented herein are not inherently relatedto any particular computer or other apparatus. In particular, variousgeneral-purpose machines may be used with programs written in accordancewith the teachings herein, or it may be more convenient to construct amore specialized apparatus to perform the required method steps. Aparticular structure for a variety of these machines will be apparent tothose of ordinary skill in the art based on the description given below.

Embodiments of the present invention as described above employ variousprocess steps involving data stored in computer systems. These steps arethose requiring physical manipulation of physical quantities. Usually,though not necessarily, these quantities take the form of electrical ormagnetic signals capable of being stored, transferred, combined,compared and otherwise manipulated. It is sometimes convenient,principally for reasons of common usage, to refer to these signals asbits, bitstreams, data signals, instruction signals, values, elements,variables, characters, data structures or the like. It should beremembered, however, that all of these and similar terms are to beassociated with the appropriate physical quantities and are merelyconvenient labels applied to these quantities.

Further, the manipulations performed are often referred to in terms suchas identifying, fitting or comparing. In any of the operations describedherein that form part of the present invention these operations aremachine operations. Useful machines for performing the operations ofembodiments of the present invention include general purpose digitalcomputers, processors, modems or other similar devices. In all cases,there should be borne in mind the distinction between the method ofoperations in operating a computer and the method of computation itself.Embodiments of the present invention relate to method steps foroperating a computer in processing electrical or other physical signalsto generate other desired physical signals.

In addition, embodiments of the present invention further relate tocomputer readable media that include program instructions for performingvarious computer-implemented operations. The media and programinstructions may be those specially designed and constructed for thepurposes of the present invention, or they may be of the kind well knownand available to those having skill in the computer software arts.Examples of computer-readable media include, but are not limited to,magnetic media such as hard disks, floppy disks, and magnetic tape;optical media such as CD-ROM disks; magneto-optical media such asfloptical disks; and hardware devices that are specially configured tostore and perform program instructions, such as read-only memory devices(ROM) and random access memory (RAM). Examples of program instructionsinclude both machine code, such as produced by a compiler, and filescontaining higher level code that may be executed by the computer usingan interpreter.

FIG. 11 illustrates a typical computer system that can be used by a userand/or controller in accordance with one or more embodiments of thepresent invention. The computer system 1100 includes any number ofprocessors 1102 (also referred to as central processing units, or CPUs)that are coupled to storage devices including primary storage 1106(typically a random access memory, or RAM), primary storage 1104(typically a read only memory, or ROM). As is well known in the art,primary storage 1104 acts to transfer data and instructionsuni-directionally to the CPU and primary storage 1106 is used typicallyto transfer data and instructions in a bi-directional manner. Both ofthese primary storage devices may include any suitable of thecomputer-readable media described above. A mass storage device 1108 alsois coupled bi-directionally to CPU 1102 and provides additional datastorage capacity and may include any of the computer-readable mediadescribed above. The mass storage device 1108 may be used to storeprograms, data and the like and is typically a secondary storage mediumsuch as a hard disk that is slower than primary storage. It will beappreciated that the information retained within the mass storage device1108, may, in appropriate cases, be incorporated in standard fashion aspart of primary storage 1106 as virtual memory. A specific mass storagedevice such as a CD-ROM may also pass data uni-directionally to the CPU.

CPU 1102 also is coupled to an interface 1110 that includes one or moreinput/output devices such as such as video monitors, track balls, mice,keyboards, microphones, touch-sensitive displays, transducer cardreaders, magnetic or paper tape readers, tablets, styluses, voice orhandwriting recognizers, or other well-known input devices such as, ofcourse, other computers. Finally, CPU 1102 optionally may be coupled toa computer or telecommunications network using a network connection asshown generally at 1112. Connection 1112 may be used to communicate withthe DSL system and/or modems of interest. In some cases, the computersystem 1100 may have a proprietary, dedicated and/or otherwise specificconnection with the DSL system, perhaps through an operator's facilities(for example, a CO) or in some other suitable manner (for example,connecting to the NMS of a given DSL system). With such connections, itis contemplated that the CPU might receive information from the networkand/or DSL system, or might output information to the network and/or DSLsystem in the course of performing the above-described method steps. Theabove-described devices and materials will be familiar to those of skillin the computer hardware and software arts. The hardware elementsdescribed above may define multiple software modules for performing theoperations of this invention. For example, instructions for running amargin monitoring and control controller may be stored on mass storagedevice 1108 (which may be or include a CD-ROM) and executed on CPU 1102in conjunction with primary memory 1106 and a suitable computer programproduct in use on system 1100. In a preferred embodiment, the controlleris divided into software submodules.

The many features and advantages of the present invention are apparentfrom the written description, and the appended claims are intended tocover all such features and advantages of the invention. Further, sincenumerous modifications and changes will readily occur to those skilledin the art, the present invention is not limited to the exactconstruction and operation as illustrated and described. Therefore, theembodiments described should be taken as illustrative, not restrictive,and the invention should not be limited to the details given herein butshould be defined by the following claims and their full scope ofequivalents, whether foreseeable or unforeseeable now or in the future.

1. A method for configuring a first DSL system, the method comprising:collecting operational data pertaining to the first DSL system, whereinthe first DSL system is configured to operate with a first profile;obtaining binder-level information; selecting a second profile, whereinthe second profile is one of a plurality of allowed profiles based onthe binder-level information; determining whether the first DSL systemis capable of operating with the second profile based on the collectedoperational data and one or more transition rules, wherein the secondprofile is an available profile for transition from the first profile;and if the first DSL system is capable of operating with the secondprofile based on the collected operational data and the one or moretransition rules, then instructing the first DSL system to operate withthe second profile.
 2. The method of claim 1 further comprising: if thefirst DSL system is not capable of operating with the second profilebased on the collected operational data and one or more transitionrules, selecting a third profile, wherein the third profile is anallowed profile based on the binder-level information; determiningwhether the first DSL system is capable of operating with the thirdprofile based on the collected operational data and the one or moretransition rules, wherein the third profile is an available profile fortransition from the first profile; and if the first DSL system iscapable of operating with the third profile based on the collectedoperational data and the one or more transition rules, then instructingthe first DSL system to operate with the third profile.
 3. The method ofclaim 1 wherein the operational data comprises data pertaining to atleast one of the following: band preference indication; margin cap modeindication; indication that margin per tone should be kept smaller thanthe maximum SNR margin; service priorities pertaining to net data rate;service priorities pertaining to excess margin; service prioritiespertaining to excess margin per tone; service priorities pertaining todelay; service priorities pertaining to impulse noise protection;indication of loading algorithms used with the first DSL system;indication of power allocation algorithms used with the first DSLsystem; maximum attainable data rate; current data rate; margin; channelattenuation per tone; average attenuation; quiet line noise per tone;active line noise per tone; SNR per tone; transmitted PSD per tone;DPBOSHAPED; UPBOSHAPED; echo response; band preference; margin cap mode;FEC correction count; code violation count; errored seconds; severelyerrored seconds; number of retrainings count; current delay; errordistributions; current impulse noise protection; or FEC and interleavingparameters.
 4. The method of claim 1 wherein the operational data iscollected from at least one of the following: a controller that controlsthe first DSL system; a controller that controls one or more neighboringDSL systems; a controller that controls a DSL system other than thefirst DSL system; or a private operational data source; or a publicoperational data source.
 5. The method of claim 1 wherein the firstprofile and the second profile each comprise at least one of thefollowing configuration parameters: maximum nominal power spectraldensity; MAXNOMPSD; maximum nominal aggregate transmit power; MAXNOMATP;power cutback; PCB; DPBOSHAPED; downstream power back-off shapedparameters; UPBOSHAPED; upstream power back-off shaped parameters; finegains; gi; transmit spectral scaling factors; tssi; power spectraldensity mask; PSDMASK; power spectral density level; maximum receivedpower; MAXRXPWR; upstream power “back-off” parameters; UPBOKLE; margincap mode; carrier mask; CARMASK; minimum impulse noise protection;MININP; maximum delay; MAXDELAY; target margin; TARSNRM; minimum margin;MINSNRM; maximum margin; MAXSNRM; band preference indication; PREFBAND;target data rate; minimum data rate; maximum data rate; FEC andinterleaving parameters; per tone bit cap; BCAP[n]; per tone targetmargin; TARSNRM[n]; reference noise; or REFNOISE.
 6. The method of claim1 wherein the first profile comprises a first profile minimum data rateand a first profile maximum data rate; further wherein the secondprofile comprises a second profile minimum data rate and a secondprofile maximum data rate; and further wherein the first profile and thesecond profile meet one of the following conditions: a first conditionin which the first profile minimum data rate is smaller than or equal tothe second profile minimum data rate and the first profile maximum datarate is smaller than the second profile maximum data rate; or a secondcondition in which the second profile minimum data rate is smaller thanor equal to the first profile minimum data rate and the second profilemaximum data rate is smaller than the first profile maximum data rate.7. The method of claim 1 wherein the collected operational datacomprises a parameter value set comprising one or more parameter valuesand further wherein the transition rules comprise comparing anoperational value to a threshold value, wherein the operational value isat least one of the following: a single parameter value in the parametervalue set; a calculated value based on one or more parameter values inthe parameter value set; or a combination of parameter values in theparameter value set.
 8. The method of claim 1 wherein the binder-levelinformation comprises binder-level deployment information comprising:first deployment information about the first DSL system; and neighboringdeployment information about one or more neighboring DSL systems thatare physically close to the first DSL system.
 9. The method of claim 8wherein the binder-level deployment information comprises at least oneof the following: an indication of whether the first DSL system isdeployed from a central office, a remote terminal, a service accessinterface, an optical network unit, or a remote DSLAM; or an indicationof whether a neighboring DSL system is deployed from a central office, aremote terminal, a service access interface, an optical network unit, ora remote DSLAM.
 10. The method of claim 8 wherein the allowed profilesinclude profiles with at least one of the following characteristics: oneor more lower frequencies disabled; one or more lower frequencies havinglower PSD mask than higher frequencies; upstream power back-off enabled;one or more upstream power back-off parameters with values differentthan default values; band preference enabled; or margin cap modeenabled.
 11. The method of claim 8 wherein the allowed profiles compriseconfiguration parameter values computed through the use of a spectrumbalancing method; further wherein the spectrum balancing method uses thebinder-level deployment information; further wherein the spectrumbalancing method uses at least one of the following: an assumedworst-case loop topology; or actual topology information; and furtherwherein the spectrum balancing method uses at least one of thefollowing: assumed crosstalk coupling information; or actual crosstalkcoupling information.
 12. The method of claim 1, wherein thebinder-level information comprises binder-level topology informationcomprising: first topology information about the first DSL system; andneighboring topology information about one or more neighboring DSLsystems that are physically close to the first DSL system.
 13. Themethod of claim 12 wherein the binder-level topology informationcomprises at least one of the following: location information regardinga deployment point; location information regarding customer premisesequipment; loop length; neighborhood information; distance of adeployment point from a reference point; or distance of customerpremises equipment from a reference point.
 14. The method of claim 12wherein the allowed profiles comprise configuration parameter valuescomputed through the use of a spectrum balancing method; further whereinthe spectrum balancing method uses at least one of the following:assumed deployment information; or actual deployment information;further wherein the spectrum balancing method uses the binder topologyinformation; and further wherein the spectrum balancing method uses atleast one of the following: assumed crosstalk coupling information; oractual crosstalk coupling information.
 15. The method of claim 1 whereinthe binder-level information comprises crosstalk coupling informationbetween the first DSL system and at least one neighboring DSL systemthat is physically close to the first DSL system.
 16. The method ofclaim 15 wherein the crosstalk coupling information comprises datapertaining to at least one of the following: Xlog; Xlin; crosstalkcoupling parameters; average of Xlog over a group of tones; receivedcrosstalk noise; or received total noise.
 17. The method of claim 15further comprising collecting operational data pertaining to aneighboring DSL system; further wherein the collected operational datapertaining to the first DSL system comprises a first DSL systemparameter value set comprising one or more parameter values; furtherwherein the collected operational data pertaining to the neighboring DSLsystem comprises a neighboring DSL system parameter value set comprisingone or more parameter values; further wherein the transition rulescomprise comparing an operational value to a threshold value, whereinthe operational value is at least one of the following: a singleparameter value in the first DSL system parameter value set; a singleparameter value in the neighboring DSL system parameter value set; acalculated value based on one or more parameter values in the first DSLsystem parameter value set; a calculated value based on one or moreparameter values in the neighboring DSL system parameter value set; acombination of parameter values in the first DSL system parameter valueset; or a combination of parameter values in the neighboring DSL systemparameter value set.
 18. The method of claim 15 wherein the allowedprofiles comprise configuration parameter values computed through theuse of a spectrum balancing method, further wherein the spectrumbalancing method uses at least one of the following: assumed deploymentinformation; or actual deployment information; further wherein thespectrum balancing method uses at least one of the following: actualtopology information; or assumed topology information; and furtherwherein the spectrum balancing method uses the crosstalk couplinginformation.
 19. A computer program product comprising: a machinereadable medium and program instructions contained in the machinereadable medium, the program instructions specifying a method forconfiguring a first DSL system, the method comprising: obtainingoperational data from the first DSL system, wherein the first DSL systemis configured to operate with a first profile; obtaining binder-levelinformation, wherein the binder-level information comprises at least oneof the following: actual or assumed binder-level deployment information;actual or assumed binder-level topology information; or actual orassumed crosstalk coupling information; selecting a second profile,wherein the second profile is: allowed based on the binder-levelinformation; allowed based on transition rules; and usable by the firstDSL system based on the collected operational data; and instructing thefirst DSL system to operate with the second profile.
 20. The computerprogram product of claim 18 wherein the second profile comprises one ormore configuration parameter values computed using a spectrum balancingmethod performed using the binder-level information.
 21. A controllercomprising: a data collection unit coupled to a data analysis unit and acontrol signal generator coupled to the data analysis unit, wherein thedata collection unit, the data analysis unit and the signal generatorare configured to: collect operational data pertaining to a first DSLsystem, wherein the first DSL system is configured to operate with afirst profile; obtain binder-level information; select a second profile,wherein the second profile is one of a plurality of allowed profilesbased on the binder-level information; determine whether the first DSLsystem is capable of operating with the second profile based on thecollected operational data and one or more transition rules, wherein thesecond profile is an available profile for transition from the firstprofile; and instruct the first DSL system to operate with the secondprofile only when the first DSL system is capable of operating with thesecond profile based on the collected operational data and the one ormore transition rules.